The massive — and pressing — need to shore up US infrastructure is undeniable. A dearth of investment in recent years has exacerbated the imperative to act now. In response, some 25 states have enacted legislation to enable private-sector participation in infrastructure projects. These public-private partnerships (PPPs), already commonplace in many parts of the world, combine the best of public-sector governance with the most valuable of private-sector efficiencies. And US investors are beginning to show an increasing appetite for PPPs because infrastructure investments provide relative stability.